Oil filler plug with vent passage

ABSTRACT

A combined oil filler and breather plug comprising a body adapted for removable attachment to an oil exit port on a machine casing, and ventilating passage means within the body which, when the body is attached to said oil input port, connect the inside of said machine casing to an exit port or ports at the exterior of said body a filter element formed from an interstitial plastics material being located externally of the plug body so as to completely enclose said exit port or ports of the ventilating passage means whereby air passing through the plug to the machine casing must pass through the filter.

United States Patent [72] inventors William W. Butler Hull, England;Harvey l-loltby, Hull, England; Graham J. T. Plnder, North Ferriby,England; Sidney J. Moore, Willerby, England; Bernard Faulkner, deceased,late of Willerby, England by Violet E. Faulkner, legal representative[2] 1 Appl. No. 853,390 22 1 Filed Aug. 27, 1969 [45] Patented Nov. 23,I971 [73] Assignee J. H. Fenner & Company Limited Hull, England (32]Priority Aug. 31, 1968 [3 3 Great Britain 31 1 41708/68 a [54] Oil.FILLER PLUG WITH VENT PASSAGE 6 Claims, 1 Drawing Fig. [52] US. Cl220/44, 55/510 51 |m.c| 865d 51/16 [50] Field oi Search 220/44; 55/507,505, 510

Primary Examiner-George T. Hall AnorneyBeveridge & De Grandi ABSTRACT: Acombined oil filler and breather plug comprising a body adapted forremovable attachment to an oil exit port on a machine casing, andventilating passage means within the body which, when the body isattached to said oil input port, connect the inside of said machinecasing to an exit port or ports at the exterior of said body a filterelement formed from an interstitial plastics material being locatedexternally of the plug body so as to completely enclose said exit portor ports of the ventilating passage means whereby air passing throughthe plug to the machine casing must pass through the filter.

PATENTEDunv 23 IBYI 3,622 033 IN VENTORSI WILLIAM ws-LLs Bunm,

HARVEY HoLTBy, GRAHAnJEREHY Tuomvsou Finns- SIDNEY JACK MOORE,

and

BERNARD FAULKNER 01]. FILLER PLUG WITH VENT PASSAGE The presentinvention relates to oil filler plugs for machine casings andparticularly to oil filler plugs which are additionally adapted tofunction as breather elements.

Combined filler and breather plugs are known which incorporate filterelements made of compressed paper or sintered bronze. However such knownplugs tend to be expensive to produce.

According to the present invention a combined oil filler and breatherplug comprises a body adapted for removable attachment to an oil inputport on a machine casing, and ventilating passage means within the bodywhich, when the body is attached to said oil input port, connect theinside of said machine casing to an exit port or ports at the exteriorof said body, a filter element formed from an interstitial plasticsmaterial being located externally of the plug body so as to completelyenclose said exit port or ports of the ventilating passage means wherebyair passing through the plug to the machine casing must pass through thefilter element.

Preferably the plug body includes an externally screwthreaded portionadapted to engage a mating screw-threaded portion on said machinecasing.

Conveniently, the filter element is cylindrical and is rigidly heldbetween a shoulder portion of the plug body and a cap screwed onto theplug body.

Preferably the plug is made from a rigid synthetic plastics materialsuch as that sold under the registered trademark DELRIN," but mayequally well be metallic.

Advantageously, the plug body is fonned to display a hexagonalconfiguration over at least a part of its length in order to facilitatethe tightening of the screw by means of a suitable hand tool.

The invention will be further described, by way of example, withreference to the accompanying drawing which is a sectional elevation ofone embodiment of a combined oil filler and breather plug constructed inaccordance with the present invention.

The combined plug shown in the drawing has a body 1 comprising asubstantially cylindrical center portion 2, an externally screw-threadedtapered projection 3 and a generally cylindrical neck portion 4. Theplug 1 has an axial bore 5 which is connected to one or more radiallydirected passages 6 in the walls of the neck portions 4, two suchpassages 6 being shown in the drawing.

A metal cap 9 is secured to the plug 1 by a screw 7 which is received ina screw-threaded bore 8 in the neck portion 4, the bore 8 extendingaxially of the plug 1 and communicating with the bore 5.

A cylindrical filter element 10 is rigidly held between the cap 9 and ashoulder 1] on the center portion 2, the filter element 10 beingembraced and protected towards the outside by a cylindrical coverportion 12 of the cap 9, this cover portion 12 being coaxial with theplug body 1. The cylindrical filter l and the external surface of theneck portion 4 define an annular space 13 which communicates with thebore via the passages 6.

In use, the tapered portion 3 of the plug 1 is screwed into the oilinput port of the machine casing. The metal cap 9 may be released toallow the filter to be removed or changed by removing the screw 7.

When the cap is in place, as shown in the drawing, an airtight abuttingrelationship exists between the filter element 10 and both the shoulder11 and the metal cap 9 so that air drawn into the machine must passthrough the filter 10, the passages 6 and the bore 5. Any solidparticles are thus trapped by the filter element 10 and prevented fromentering the machine where they could possibly cause damage to bearingsor other machine parts.

In a further embodiment the cylindrical body portion 2 described withreference to the drawing is formed to have a hexagonal configurationover at least a part of its length in order to facilitate the tighteningof the screw by means of a suitable hand tool.

Conveniently the plug 1 is made from a rigid synthetic plastics materialsuch as that sold under the registered trademark Delrin," but it canequally well be made in any suitable metallic or nonmetallic material.

We claim:

1. A combined oil filler and breather plug comprising a plug body, screwthread means on the plug for attaching the plug body to an oil inputport on a machine casing, ventilation passage means within the plugbody, exit port means for the ventilating passage means which arelocated at the exterior of said plug body and which, when the plug bodyis attached to said oil input port, are connected to the inside of themachine casing by said ventilating passage means, a shoulder formed onthe plug body, a cap releasably attached to the plug body, and acylindrical filter element formed from an interstitial plastics materialbeing rigidly located between said shoulder on the plug body and the capso as to completely enclose exit port means.

2. A plug according to claim 1 in which at least one radially directedpassage connects the exit port means to said ventilating passage means,and in which the ventilating passage means comprises an axial bore insaid plug body.

3. A plug according to claim 2 in which said plug body comprises agenerally cylindrical center portion, an externally screw-threadedprojection on said center portion serving for connecting the plug bodyto said machine casing, and a generally cylindrical neck portionextending from said center portion in which said exit port means arelocated.

4. A plug according to claim 2 in which said plug body comprises acenter portion of generally hexagonal configuration to facilitatetightening of the plug onto said machine casing by means of a suitablehand tool, an externally screw-threaded projection on said centerportion serving for connecting the plug body to said machine casing, anda generally cylindrical neck portion extending from said center portionin which said exit port means are located.

5. A plug according to claim 3 wherein an formed between said filter andsaid neck body.

6. A plug according to claim 5 in which a cylindrical cover portion isprovided on the cap which is coaxial with the plug body and whichembraces the filter to provide protection therefor.

annular space is portion of the plug

1. A combined oil filler and breather plug comprising a plug body,screwthread means on the plug for attaching the plug body to an oilinput port on a machine casing, ventilation passage means within theplug body, exit port means for the ventilating passage means which arelocated at the exterior of said plug body and which, when the plug bodyis attached to said oil input port, are connected to the inside of themachine casing by said ventilating passage means, a shoulder formed onthe plug body, a cap releasably attached to the plug body, and acylindrical filter element formed from an interstitial plastics materialbeing rigidly located between said shoulder on the plug body and the capso as to completely enclose exit port means.
 2. A plug according toclaim 1 in which at least one radially directed passage connects theexit port means to said ventilating passage means, and in which theventilating passage means comprises an axial bore in said plug body. 3.A plug according to claim 2 in which said plug body comprises agenerally cylindrical center portion, an externally screw-threadedprojection on said center portion serving for connecting the plug bodyto said machine casing, and a generally cylindrical neck portionextending from said center portion in which said exit port means arelocated.
 4. A plug according to claim 2 in which said plug bodycomprises a center portion of generally hexagonal configuration tofacilitate tightening of the plug onto said machine casing by means of asuitable hand tool, an externally screw-threaded projection on saidcenter portion serving for connecting the plug body to said machinecasing, and a generally cylindrical neck portion extending from saidcenter portion in which said exit port means are located.
 5. A plugaccording to claim 3 wherein an annular space is formed between saidfilter and said neck portion of the plug body.
 6. A plug according toclaim 5 in which a cylindrical cover portion is provided on the capwhich is coaxial with the plug body and which embraces the filter toprovide protection therefor.